Do you see a point where this strategy of adding functional space reduces its value factor?

The function of individual leases (which do not designate bedrooms) is to provide the tenant the peace of mind that they will not be held financially liable for non-payment by the other occupants, and to give us the ability to take enforcement action against individual occupants without having to involve the other residents.

If you do propose to stay involved with the deal, what are your qualifications that would lead an investor to engage you in performing the functions you see yourself executing?

@Thomas N.I've used a clause in my lease to the effect that "tenant understands and acknowledges that the fireplace is for decorative purposes and is not functional."  

I've thought of starting 4+ discussions now and after using the search function have found that the topic has already been discussed!

It is applicable because it is a similar support function to real estate. 

People who do not function from that scope of thinking have made wherever they invest work.

I know vacancy is a function of hundreds of factors, but in general, a property in close proximity to Ohio Stadium, downtown, the Convention Center, etc, - what is a conservative overall vacancy estimate for the year when used as an Air BnB type rental?

If one partner puts in more money than the other, you could change ownership interests, you could treat it as a loan, you could reduce income/profits from the non-contributing partner until the contributing partner is paid, etc.You will want to discuss with each other who will be doing what management functions and whether that is worth anything to you both.

After a few months, the tenant has reached out saying that the glowing ring no longer turns on, and is stating that it is no longer functional.